Micrometer



June 29, 1937. E. MULLER 2,085,380

MICROMETER Filed June 29, 1955 FICE- 1 F'IIi-E- JNVENToR. f/'Nes/ Mu/ er BY M @Tomi/vtm Patented June 29, 1937 UNITED STATES PATENT OFFICE Application June 29,

5 Claims.

The invention relates to measuring devices such as a micrometer for accurately setting a calliper or other measuring instrument.

An object of the invention is to provide a device of the character described which may be quickly and readily set in adjusted position and which will provide an improved means for holding the movable parts thereof in such adjusted positions.

Another object of the invention is to provide a micrometer or measuring device of the character described which will not become clogged or other- `wise have its operation interfered with by presence of grease or grit or the like.

A further object of the invention is to provide a measuring device of the character above which will aiford an improved means for effecting minor adjustments in the length thereof for compensating for any wear of the device or for any slight imperfection in its manufacture.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawing accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawing and description may be adopted within the scope of the invention as set forth in the claims.

Referring to said drawing:

Figure 1 is a side elevation of the micrometer constructed in accordance with the present i11- vention.

Figure 2 is an end view of the device shown in Figure l.

Figure 3 is a longitudinal sectional view of the device shown in Figure 1.

Figures 4 and 5 are transverse sectional views of the device and are taken substantially on the planes of lines 4 4 and 5 5 respectively of Fig- Figure 6 is a plan view of one of the sections of the device` Figure '7 is a side elevation of a wrench suitable for use in effecting the adjustment of certain parts of the device.

The micrometer shown in the accompanying drawing comprises a cylindrical body member 8 provided with a bore longitudinally therethrough consisting of a reduced portion 9 adjacent an end II of the body and an enlarged portion I2 which extends from adjacent such end to the other end I3 of the body. The inner periphery of the enlarged bore portion I2 is threaded and is arranged to receive the threaded periphery of 1935, Serial N0. 29,010

a split tubular member I4 over which is pressed at its outer end a sleeve I 6, the latter being adapted to move longitudinally with the member It but over the outer periphery of the body 8.

As will be clear from Figure 1, the exterior 5 side of the member 8 is provided with a series of graduations Il which cooperate with the end I8 of the sleeve and with circumferentially spaced graduations I9 thereon for computing the relative positioning of the sleeve on the body member.

Slidably mounted in the reduced bore portion 9 of the body member and extendible from the end II is a cylindrical shank 2I which is arranged to be set in a plurality of fixed longitudinal posi- 15 tions with respect to the body member. To expedite such setting, the shank is provided with a plurality of transversely extending recess portions 22 which are arranged to receive the inner end of a set screw 23 carried by the body member 8. Preferably the recess portions 22 are flared towards the periphery of the shank and the inner end of the set screw 23 is tapered so that an automatic movement of the shank will be elected to properly align the recess portions 25 and set screw when the latter is advanced to engage any portion of the recess, thus permitting the ready and accurate setting of the shank, even though the recessed portion and set screw are not initially in perfectly aligned relation. I have found that there is a tendency for oil and other material to enter and eventually pack in the recessed portions of the shank, which if allowed to remain may have an abrasive action against the sides of the recesses and the set screw subject to relative movement thereof and may likely prevent an accurate setting of the shank. This accumulation of material in the recessed portions has been completely eliminated in the present device by the extension of the recessed portions completely through the shank so as to prevent any packing of such material therein. Also, as will be understood, the extension of these openings completely through the shank permits of the ready cleaning of the openings and thereby insures a perfect fitting between the openings and the lower end of the set screw at all times.

In accordance with the present arrangement,

I have further provided for an improved means of tightly holding the set screw in one of the openings or recessed portions 22 so that unless manually released the device will stay in adjusted position substantially indefinitely. This feature is carried out by the use of a tubular extension 24 tightly and Xedly threaded transverse- 55 ly through the body member from the bore 9 and adjacent the end il and which is split lengthwise thereof and provided with a threaded outer periphery. The set screw 23 is comprised of a pin 26 which is slidably carried in the extension 2Q and joined at its outer end with a sleeve 2l which is threaded over its inner periphery for engagement with the outer periphery of the extension 24. Thus, as will be clear, on rotating the sleeve 2l the lower end of the pin may be advanced into oneof the openings or recessed portions 22 of the shank and upon the application of a further rotative force the sleeve 21 will be backed up against the threads on the outer periphery of the extension 24 which by reason of their incline will serve to tightly contract the extension about the pin therein, thus tightly binding both the pin in the extension and the engaged threaded portions of the sleeve and extension.

As will be understood, the measured distance provided by the device is taken between the outer extremities of the shank and the tubular member ift. In the present enbodiment the measuring points are comprised of the heads 28 and 29 of screws 3| and 32 which are tightly threaded into the ends of the shank and member to permit slight adjustment thereof to compensate for any discrepancy in the length of the measured distance occasioned by wear or by any imperfection in the manufacture of the device or the like. Preferably the screw head 28 is of a larger diameter than the shank so that the same will cooperate with the end Il of the body member to provide a stop to limit the inward movement of the shank. While the adjustment of the screws may be 'effected by substantially any means desired, I prefer to use a socket wrench 33 which is arranged to fit over the heads of the screws and is provided with inwardly projecting shoulders Sii for engagement ina plurality' of circumferentially spaced, radially extending slots or recesses 36 in the screw heads. As will perhaps be best seen from Figures 2 and 3,' these recesses are of a depth as to position the bases thereof inwardly of the circumference of the shank thus disposing the end of the shank behind such recesses to hold the wrench in proper engagement with the head of the screw.

Preferably the positioning of the set screw 23 and openings 22 in the shank are such as to position one of the openings for engagement by the set screw when the shank is moved substantially to an innermost position with the head 3b in engagement with the end wall of the body. In the present construction a perfect alignment of the set screw and opening is purposely not effected with the members in the aforementioned position, but rather only in approximate align- -`ment as will cause the set screw on advancement to engage the outer tapered side of the opening whereby on further advancement of the set screw a slight outward movement of the shank will be effected as the set screw and opening are brought into perfect alignment. To enable the approximate positioning of the other openings in the shank with the set screw, there is preferably provided a circumferential mark 31 about the shank Vadjacent such openings and spaced Vtherefrom by a distance substantially equal to the spacing of the set screw from the end ll of the body member whereby upon moving of one of these marks into the plane Aof the end wall of the body member a substantial alignment of the set screw and the adjacent shank opening will be effected.

Also to assist in the proper alignment of the shank opening and the set screw, there is provided, in similarly angularly related positions with respect to the shank openings and set screw, a longitudinally extending mark 3S on the shank and a radial mark 39 on the end wall of the body whereby when these marks are aligned a proper rotative position of the shank in the body will obtain to insure the alignment of the openings and the set screw.

As will be further understood, the distance between the shank openings is substantially equal to the micrometer adjustment provided by the sleeve I6 over the body member. Thus, while in the present disclosure the shank is provided with but three openings or two of such unit lengths, it will be understood that the shank may be either lengthened or shortened to provide for an increase or decrease in the measurable distance of the device.

I claim:

1.A measuring` device comprising, a body, a member extendible therefrom,Y a contractible tubular extension on said body, means movable in said extension, and means engageable with said extension for positioning Asaid rst means against said member for setting same and arranged to contract said extension about said rst means.

2. A measuring device comprising, a body provided with a longitudinally extending bore, a member slidably mounted in said bore and extendible from said body for Vvarying the length of said device, means for setting said member comprising a transverse tubular extension on said body being split lengthwise thereof and having a threaded periphery, a pin slidable in said extension, a sleeve threadably engaging the periphery of said extension and secured to said pin'for pressing the same against said member and arranged with the pin so pressed to bind against and contract said extension about said pm.

3. A micrometer comprising, a tubular body, a member threadably secured to said body and movable lengthwise relative thereto, cooperating graduations on said body and member for computing the relative lengthwise vpositions thereof, a shank slidably carried by an extendible from said body, a transversetubular extension on said body being split lengthwise thereof and having a threaded periphery, a pin movable in ,said extension, and a member threadably secured to said extension for pressing said pin against said shank and arranged with said pin so pressed to bind against and contract said extension about said pin.

4. A measuring device comprising, a body having a bore opening to a side thereof, a shank mounted in'said bore and extendible therefrom for varying the distance between the ends Vof said shank and body, measuring lpoints at said ends comprising a pair of screws tightly tted in said body and shank for permitting adjustment of said distance, the screw in said shank having a head extending transversely across the end of said shank and formed with a radial slot through the head and opposite the end face of said shank for engagement with a wrench.

5. A measuring device comprising, a body having a bore opening to the side thereof, a cylindrical shank mounted in said bore and extendible from said side for Varying the distance between the ends between said shank and body, measuring points at said ends comprising a pair of screws tightly fitted in said body and shank for permitting adjustment of said distance, the screw in said shank having a head of a larger diameter than said shank and engageable With said body side for limiting the movement of the shank into said bore, said head being provided -with a radial slot extending therethrough for engagement with a Wrench, the inner end of said slot being disposed at a point within the circumference of said shank.

ERNEST MULLER. 

